Comparison of B & W 800 D and B & W 800 D3

[TLS Guy]

No, I'm not referring to the movies with updated settings. I'm indeed referring to the real thing.
Several years ago, The Met presented Verdi's Rigoletto, which was inspired by Victor Hugo's "Le Roi s'amuse", in a Las Vegas context. The fact is that they've just repeated that ridiculous venture this year with the same opera, a Cadillac on the stage at one point and dressing of the 1930's.
If this silly trend continues, some people will stop going to the opera and go back to listening to their favorite CDs and LPs at home. As a matter of fact, people have started complaining about this. TLS Guy and myself are not the only ones!

Has opera ever appealed to many young people? It has surely appealed to a greater percentage of young people in Europe. It's a question of culture. Most opera composers originated from European countries which have had longer histories than our North American civilization.

I studied classical singing and I sang as a lyric tenor in opera productions as a passionate hobby.
My father was listening every Saturday to Met radio broadcasts, and this how I got to like opera. I eventually found that I had the vocal organ to sing in such art form. My two children, however, were not appealed very much to it.

Well greetings to you as well. I thought you were an opera buff by your "handle". I love opera. In my student days, tickets to Covent Garden or the ENO were a real luxury.

With a busy ICU practice and continuous short staffing, trips to the Twin Cities for opera were far and few between. I have manged to get the the Met once!

Now I'm able to get to the Minnesota Opera at the Ordway in St. Paul more often now I'm retired. Out Eagan Town home comes in handy for that. Unfortunately the Ordway has very poor dry acoustics, and does not sound as good as my sound system!

So I have got to know opera from radio, especially Met broadcasts, LPS and then CDs. Now I get my fill from DVDs and especially BDs, and also Met Player.

To be honest I prefer opera in my home theater then the opera house. I find I'm much more drawn into the production on the TV screen, and the audio is better then all but the very best seats in the house. I'm lucky that my rig can deliver the full impact of a large orchestra singers and chorus without distress.

Now that all this is possible, I'm particularly peeved at the antics of a lot of opera directors and their stage directors. Wagner seems to come in for particular abuse. The Met staging of Parsifal in a post apocalyptic staging was a particular travesty.

Marek Janowski was interviewed on the BPO Digital Concert Hall and he said he had stopped conducting opera because of the antics of opera directors.

Sometimes updating the time frame does work though, I enjoyed Falstaff set in the fifties from the Met.
The Glyndebourne Handel Giulio Cesare in Egitto set in the eighteenth century I thought worked rather well. I really like those discs. Just a wonderful performance.

As far as the scene in Minnesota, I'm glad to say we get lots of younger people at the opera and the Minnesota and SPCO concerts. So I'm not really concerned for the future.

Anyhow we digress as this is a thread about B & Ws latest flagship offering.

 

[Dennis Murphy]

No, I'm not referring to the movies with updated settings. I'm indeed referring to the real thing.
Several years ago, The Met presented Verdi's Rigoletto, which was inspired by Victor Hugo's "Le Roi s'amuse", in a Las Vegas context. The fact is that they've just repeated that ridiculous venture this year with the same opera, a Cadillac on the stage at one point and dressing of the 1930's.
If this silly trend continues, some people will stop going to the opera and go back to listening to their favorite CDs and LPs at home. As a matter of fact, people have started complaining about this. TLS Guy and myself are not the only ones!

Has opera ever appealed to many young people? It has surely appealed to a greater percentage of young people in Europe. It's a question of culture. Most opera composers originated from European countries which have had longer histories than our North American civilization.

I studied classical singing and I sang as a lyric tenor in opera productions as a passionate hobby.
My father was listening every Saturday to Met radio broadcasts, and this how I got to like opera. I eventually found that I had the vocal organ to sing in such art form. My two children, however, were not appealed very much to it.

Well, just so you don't think there are only two opera nuts on the board, I certainly qualify as one. And the Audioholics vote is 2:1 against me on modern stagings. I saw the Met's Las Vegas setting and thought it was a brilliant conception and beautifully executed. After all, the whole plot is pretty silly--not many dying sopranos sing their guts out inside of a bag. It's a little more believable coming out of the trunk of a Coupe De Ville. Also remember that Verdi had to move the settings from what he wanted to what he could get past the censors.

 

[TLS Guy]

Well, just so you don't think there are only two opera nuts on the board, I certainly qualify as one. And the Audioholics vote is 2:1 against me on modern stagings. I saw the Met's Las Vegas setting and thought it was a brilliant conception and beautifully executed. After all, the whole plot is pretty silly--not many dying sopranos sing their guts out inside of a bag. It's a little more believable coming out of the trunk of a Coupe De Ville. Also remember that Verdi had to move the settings from what he wanted to what he could get past the censors.

Well three's a crowd!

On the whole I prefer opera to be in period. I'm not totally against a time shift, but it must not be full of gratuitous political innuendo and statements. Sometimes severe violence is done to the plot. I have a DVD set of Tristan und Islode and the opera director had the nerve to change the ending and totally ruin the opera and especially Isolde's "love death."

I would not call the plot of Rigoletto silly. It is about father daughter relationships, a common theme for Verdi, and sexual predation. I have not seen that production by the way, but I will see if it is on Met Player.

 

[Art Vandelay]

The spectral decay measurement is better.

I measured those speakers very carefully last Saturday, and spent a lot of time doing it. I can not confirm John A's 5 db peak centered on 10 KHz.

I did note a slight dip in response centered on 5 KHz. The off axis response was good until 90 degrees off axis. I concur with John A that the off axis response does fall off in the higher frequencies, but still mirrors the on axis response until 90 degrees off axis.

What I heard is much more consistent with my measurements then John A's.

This speakers are not forward like the previous speakers. They are very slightly retiring, which in my view is a good fault. The sound stage is behind the plane of the speakers which is as it should be for a speaker which will be used for classical music.

The bass is much tighter and sounds lower Q than the 800 D.

My impression was of a very pleasant and non fatiguing speaker to listen to.

I still think that they should issue an active version of this speaker.

I will be back in the Twin Cities the weekend after next. My current woofer tester does not work with Windows 10. I have ordered the new just released Dayton tester and will measure the impedance curve and phase angles then.

 

[Art Vandelay]

I measured those speakers very carefully last Saturday, and spent a lot of time doing it. I can not confirm John A's 5 db peak centered on 10 KHz.

I did note a slight dip in response centered on 5 KHz. The off axis response was good until 90 degrees off axis. I concur with John A that the off axis response does fall off in the higher frequencies, but still mirrors the on axis response until 90 degrees off axis.

What I heard is much more consistent with my measurements then John A's..

If you're referring to 802D3, what you should see in the measurements are small dips at 5-6kHz and 2-3 kHz.

The reason being that the crossover is 2nd + first order electrical, and the tweeter is moved a half wavelength forward rather than inverted for phase coherence. The side effect though is that the tweeter and FST mid are only in phase over the small region between 3 and 5kHz. I think B&W would have been better to invert the tweeter polarity and position it in time alignment with the FST.

Fortunately, the dip at 6kHz pretty much disappears at 15-20 degrees off axis, which is B&W's intended axis for listening. Likewise, the peak at 10kHz is tamed off axis.

However, the dip at 2.5kHz remains, particularly at the reference listening height which is just below the tweeter - unless it's been corrected in the 800D3, but I think there's the same single cap in series with the tweeter.

With my 800D2's, I designed and installed an impedance correction network which flattens the tweeter's primary coil resonance, and has the added benefit of partly correcting the phase alignment at 2-3kHz as well as creating the ideal 2nd order acoustic response roll-off below 4kHz. The other issue with the 800D2 is the peak at 3-4kHz. About 1.5dB of the peak is created by the crossover design but the rest of it is due to a small driver resonance. Fortunately, the 3dB of driver contribution can be corrected by installing a notch filter (RLC) in shunt with the driver, and when you get the Q exactly correct the response is near flat and the time domain distortions are also corrected.

In order to gauge the effect of both mods I initially used some speaker cable so that they were external to the speakers and could be switched in and out from the listening chair.

FWIW, the difference in-vs-out isn't huge but is audible and makes for better tonal balance as well as coherence and sound stage depth. To put it simply, it's a more live experience and aside from the bass it makes my D2 sound much more similar to the D3.

See attached images of the tweeter response with and without my correction network.

 

[TLS Guy]

If you're referring to 802D3, what you should see in the measurements are small dips at 5-6kHz and 2-3 kHz.

The reason being that the crossover is 2nd + first order electrical, and the tweeter is moved a half wavelength forward rather than inverted for phase coherence. The side effect though is that the tweeter and FST mid are only in phase over the small region between 3 and 5kHz. I think B&W would have been better to invert the tweeter polarity and position it in time alignment with the FST.

Fortunately, the dip at 6kHz pretty much disappears at 15-20 degrees off axis, which is B&W's intended axis for listening. Likewise, the peak at 10kHz is tamed off axis.

However, the dip at 2.5kHz remains, particularly at the reference listening height which is just below the tweeter - unless it's been corrected in the 800D3, but I think there's the same single cap in series with the tweeter.

With my 800D2's, I designed and installed an impedance correction network which flattens the tweeter's primary coil resonance, and has the added benefit of partly correcting the phase alignment at 2-3kHz as well as creating the ideal 2nd order acoustic response roll-off below 4kHz. The other issue with the 800D2 is the peak at 3-4kHz. About 1.5dB of the peak is created by the crossover design but the rest of it is due to a small driver resonance. Fortunately, the 3dB of driver contribution can be corrected by installing a notch filter (RLC) in shunt with the driver, and when you get the Q exactly correct the response is near flat and the time domain distortions are also corrected.

In order to gauge the effect of both mods I initially used some speaker cable so that they were external to the speakers and could be switched in and out from the listening chair.

FWIW, the difference in-vs-out isn't huge but is audible and makes for better tonal balance as well as coherence and sound stage depth. To put it simply, it's a more live experience and aside from the bass it makes my D2 sound much more similar to the D3.

See attached images of the tweeter response with and without my correction network.

I measured the B & W 800 D3

 

[Art Vandelay]

I measured the B & W 800 D3

OK, interesting. And now that I've read your review on page 1 I'm up to speed.

FTR, here is a MLS measurement of my 800D2 (above 500Hz) taken at a distance of about 1m, on axis and just below tweeter height.

 

[Art Vandelay]

For those interested, a swept sine distortion measurement of the 800D2. It gets a bit nasty below 100Hz, but above 200Hz it's outstanding at low to moderate SPL. (chart ref 2.87V, 1m). The old Kevlar FST is really an excellent driver, in spite of the bashing it gets on audio forums.


Where the new D3 model excels is below 200Hz, and subjectively it's easy to hear the 10dB less distortion.

.....

 

[PENG]

For those interested, a swept sine distortion measurement of the 800D2. It gets a bit nasty below 100Hz, but above 200Hz it's outstanding at low to moderate SPL. (chart ref 2.87V, 1m). The old Kevlar FST is really an excellent driver, in spite of the bashing it gets on audio forums.


Where the new D3 model excels is below 200Hz, and subjectively it's easy to hear the 10dB less distortion.
View attachment 20298 .....

That's really low spl, do you have one for 70dB or higher with Mic at 9 ft or further? I just want to see how mine compares.

 

[Art Vandelay]

That's really low spl, do you have one for 70dB or higher with Mic at 9 ft or further? I just want to see how mine compares.

Disregard the dB scale because it's not calibrated.

Fwiw, the actual level was 91dB (1W), so a measurement at 3m (10 ft) would be 10dB lower, which is 81dB SPL.

When I get some spare time though I'll rerun the tests at higher levels.

FTR, the test mic was a Earthworks M31.

 

[Beave]

For those interested, a swept sine distortion measurement of the 800D2. It gets a bit nasty below 100Hz, but above 200Hz it's outstanding at low to moderate SPL. (chart ref 2.87V, 1m). The old Kevlar FST is really an excellent driver, in spite of the bashing it gets on audio forums.

Isn't it the crossover that B&W uses with that driver that gets 'bashed' on forums?

 

[TLS Guy]

Welcome Art Vandelay. You did a nice job on the 802 D2.

I now have the impedance curve and Waterfall for the 800 D3.

This is the impedance plot of the 800 D.

Not a very happy sight!

This is the impedance curve and phase angles of the 800 D3

Gone are the nasty negative phase angles and the impedance does not drop below four ohms.

This is the waterfall plot.

I have had a chance to do more extended listening. I always found the 800 Ds much too forward.

I played a disc from Hereford Cathedral. The rendition of Samuel S Wesley's Blessed be God and Father was impressive. This is one of my favorite anthems and come to that high towards the top end of my favorite compositions. The sound stage was thrown was beyond the room. The organ was distant to the choir. The two boys in the passage in descant was perfectly caught.
The sudden full organ after a "pregnant pause" really tales you by surprise the way it should and was reproduced with authority. This leads into a wonderful fugal finale for organ and chorus. The sound stage was very realistic. The 800 Ds always made a bit of a mess of that one. They were far too forward.

I also listened to a CD from the opening night of the 2016 Proms, captured from the BBC UK stream via VPN. This was Prokofiev's score for his friend Sergey Eisenstein’s patriotic film Alexander Nevsky: the cantata he fashioned from it features the dramatic Battle on the Ice.

I don't recall I have ever heard it before. It is the sort of thing that only comes along at the Proms. There was a hugely augmented BBC Symphony orchestra, with the BBC Symphony Chorus, BBC Chorus of Wales and soloists. All conducted by Sakari Oromo, who kept the pedal firmly to the metal turning in a first night to remember. I saw it with video first in iPlayer. It was quite a spectacle.

My friend Phil just loves this CD I made for him. It will give any system a monstrous work out.
The 800 D3s turn is a spectacular rendition, however I did feel at times the single mid range driver was just exhibiting early distress. This is not the sort of program to throw at a couple of bookshelves and a sub or two!

I have to say these speakers do sound very similar to my own. I don't hear distress with mine at all and the bass is fractionally more realistic I think. Since they are different rooms that is very hard to judge.

Axis and impulse 1 meter on tweeter axis.

The HF droop is due to omni mic.

Axis and off axis response. Blue axis. Black 90 degrees off axis.

Waterfall

Distortion is right around 1% at 90 db 1 meter only rising to a hair over 2% at the limits of the LF response.

Center speaker.

The axis is the blue line, which interestingly is the poorest response, probably due to cone reflections. The dip in response of these SEAS coax units centered on 9 KHz, was corrected by employing a correction network to tweeter in the upper unit, which is the BSC driver.

Waterfall.

The front three where built in 2006.

The surrounds and rear backs.

Surround FR

Axis is blue. I do not know why there is a dip at 1.5 KHz in the axis response. It is likely location.

Waterfall

Built 1984. Box and crossover designed with the help of Bullock and White's software on floppy discs using an Apple IIe. These are the first of my speakers designed with computer assistance. Final tuning by ear. I have not touched them in years. You can see by the impulse response I did not brace the box adequately. These are sealed units, and the bass ripple is a couple of db higher than calculated. They do sound a little on the warm side.

Rear back FR

I can't get off axis response due to location.

Waterfall.

These speakers were started in 1979, but did not reach final form until around 1990. It is a four way. There is an active third order crossover at 200 Hz, and a first order series crossover at 900 Hz, and a first order parallel crossover at 5 KHz. The drivers are time aligned. As you might imagine, this speaker was an absolute headache to get right. I had a lot of help from the good folk at Dynaudio. It shares a lot of design features with the Dynaudio Conquest. That speaker has the tweeter nearly on the ground because of the lobing problem and the orchestra sounds as if it is coming from below. I made the tweeter high, and this gives the effect of being in the orchestra level with the performers up onstage. Of course it has all the issues you might expect with sweet spots. However these speakers deliver a very lively and exciting sound. Baroque trumpets are really brilliant. They now make good rear backs for antiphonal SACDs. Now and again they still get a chance to shine. Although a headache, they did make me believe there is merit in time and phase alignment. However it leaves you with a lot of tricky problems to solve.
I must confess to hooking them up as a stereo pair periodically and give them a good listen. They are an exciting speaker but not over the top or sibilant.

This system has given and continues to give enormous pleasure.

I would say those 800 D3s will also deliver a lot of pleasure to fortunate owners.

 

[Art Vandelay]

Welcome Art Vandelay. You did a nice job on the 802 D2.

I now have the impedance curve and Waterfall for the 800 D3.

This is the impedance plot of the 800 D.

Not a very happy sight!

Thank you.

Re impedance, you're right; Tis shite. To make mine more amp friendly I designed a conjugate matching network which makes the impedance somewhat more resistive, but even with that it's still a challenge.

This is the impedance curve and phase angles of the 800 D3

Gone are the nasty negative phase angles and the impedance does not drop below four ohms.

This is the waterfall plot.

There's no doubt that the new model is superior, although the impedance still warrants a high current / load invariant amplifier.

My friend Phil just loves this CD I made for him. It will give any system a monstrous work out.
The 800 D3s turn is a spectacular rendition, however I did feel at times the single mid range driver was just exhibiting early distress. This is not the sort of program to throw at a couple of bookshelves and a sub or two!

It's possible but it's also possible you're hearing some stress from the tweeter too - which is high-passed with a single cap, and if it's the same design as the D2 the response is modulated by the impedance peak at coil resonance. Mine definitely sounded cleaner when I added impedance correction.

I have to say these speakers do sound very similar to my own. I don't hear distress with mine at all and the bass is fractionally more realistic I think. Since they are different rooms that is very hard to judge.


Axis and impulse 1 meter on tweeter axis.

These speakers were started in 1979, but did not reach final form until around 1990. It is a four way. There is an active third order crossover at 200 Hz, and a first order series crossover at 900 Hz, and a first order parallel crossover at 5 KHz. The drivers are time aligned. As you might imagine, this speaker was an absolute headache to get right. I had a lot of help from the good folk at Dynaudio. It shares a lot of design features with the Dynaudio Conquest. That speaker has the tweeter nearly on the ground because of the lobing problem and the orchestra sounds as if it is coming from below. I made the tweeter high, and this gives the effect of being in the orchestra level with the performers up onstage. Of course it has all the issues you might expect with sweet spots. However these speakers deliver a very lively and exciting sound. Baroque trumpets are really brilliant. They now make good rear backs for antiphonal SACDs. Now and again they still get a chance to shine. Although a headache, they did make me believe there is merit in time and phase alignment. However it leaves you with a lot of tricky problems to solve.
I must confess to hooking them up as a stereo pair periodically and give them a good listen. They are an exciting speaker but not over the top or sibilant.

This system has given and continues to give enormous pleasure.

I would say those 800 D3s will also deliver a lot of pleasure to fortunate owners.

What can I say except "really outstanding", and even that's an understatement.

It's a pity that you don't have a larger room to give them more breathing space and allow them to generate a real 3D sound stage though.

I concur too on the merits of time alignment. It's a pity that many speaker designers don't believe the merits and take up the challenge.

When I bought the 800D2's a couple of years ago, it was my aim to bypass the internal crossovers and use a DEQX or similar DSP processor with individual amplifiers. I'll get there eventually but I have some reservations over the sound quality of that approach, having since heard several DEQX systems that sounded a bit flat and lifeless in the mids and treble.

Fwiw, having said that I'll soon be bypassing the 800D2 woofer crossovers and driving them from separate class D mono amps with DSP crossovers, which I'll be able to fully optimise - as well as being able to EQ and experiment with room correction below 300Hz. As you rightly pointed out, the D3's bass alignment is far more room friendly than the D2's.

Beyond doing that, as a next step I'll configure a mini dsp to only time correct the tweeters, and will retain the passive crossover but will invert the phase to make it phase coherent.

One advantage having the tweeter so far forward in the array is that it all but eliminates the potential for
diffraction distortion, but I still regard this as a weak point in the B&W design, due to the timing and phase alignment problems that it creates above and below the crossover frequency.

 

[Art Vandelay]

Isn't it the crossover that B&W uses with that driver that gets 'bashed' on forums?

From what I've seen, both are bashed.

I appreciate the merits of the B&W design approach, but I think it creates a speaker that's more difficult than most to get sounding near perfect in typical listening spaces.

 

[TLS Guy]

Thank you.

Re impedance, you're right; Tis shite. To make mine more amp friendly I designed a conjugate matching network which makes the impedance somewhat more resistive, but even with that it's still a challenge.



There's no doubt that the new model is superior, although the impedance still warrants a high current / load invariant amplifier.




It's possible but it's also possible you're hearing some stress from the tweeter too - which is high-passed with a single cap, and if it's the same design as the D2 the response is modulated by the impedance peak at coil resonance. Mine definitely sounded cleaner when I added impedance correction.




What can I say except "really outstanding", and even that's an understatement.

It's a pity that you don't have a larger room to give them more breathing space and allow them to generate a real 3D sound stage though.

I concur too on the merits of time alignment. It's a pity that many speaker designers don't believe the merits and take up the challenge.

When I bought the 800D2's a couple of years ago, it was my aim to bypass the internal crossovers and use a DEQX or similar DSP processor with individual amplifiers. I'll get there eventually but I have some reservations over the sound quality of that approach, having since heard several DEQX systems that sounded a bit flat and lifeless in the mids and treble.

Fwiw, having said that I'll soon be bypassing the 800D2 woofer crossovers and driving them from separate class D mono amps with DSP crossovers, which I'll be able to fully optimise - as well as being able to EQ and experiment with room correction below 300Hz. As you rightly pointed out, the D3's bass alignment is far more room friendly than the D2's.

Beyond doing that, as a next step I'll configure a mini dsp to only time correct the tweeters, and will retain the passive crossover but will invert the phase to make it phase coherent.

One advantage having the tweeter so far forward in the array is that it all but eliminates the potential for
diffraction distortion, but I still regard this as a weak point in the B&W design, due to the timing and phase alignment problems that it creates above and below the crossover frequency.

I think your points are well taken. However the 800 D3 is a much better effort than what has gone before. I do think they have raised the break up point of that midrange high enough to cross it over where they have. You should be able to use a first order crossover at 4 K with a decent tweeter. The trouble is manufacturers produce not much decent data for peer review. But if the Fs of the tweeter is low enough to be 18 to 24 db down at Fs you should be OK. And if you make the Qts of the tweeter low enough you can drive it down though Fs without distress. Of course we have no idea of B & W"s tweeter Fs or Qts. This is all very short sighted as peer review would lead to better designs.

They have raised the bass driver/mid crossover point to 500 Hz which I think is a good idea.

I think the days of passive crossovers below that point are over. If you do lower the crossover pint then the speakers should be active, at least at the lower crossover point and I think you should employ two mid range drivers. I think you could also argue that reference exotic speakers should now be active.

I should tell you a bit about my dual TLS speakers since you are new to the forum.

The mid line tapers acoustically not electrically. Since there is a lot of power in the BSC signal, the BSC for the two smaller drivers is handled by the upper 10" driver active. Since there is an active crossover both drivers handle the below 60 Hz duty and the LFE signal.

The center unit has the BSC active. So there are two amps driving the center and three driving each main speakers, to a total of 750 watts per speaker.

They do indeed throw and excellent 3D image in this room. The room is 24' X 14' with 8' ceilings. So for a domestic house a fairly typical size and well proportioned. It does sound best in the second row for most music.

This is the mains middle seat second row. No room or any Eq is used.

Since transmission lines are low Q and well damped, they tend not to over excite room resonances. That is smooth enough to create a realistic sense of space with those speakers.

The surrounds are the only speakers not TL. The fronts mains are dual TLs, tuned half an octave apart. The center is a single TL. The rear TL is dual, but the short line is purposely over damped and does not speak from the port.

I do hope you become a long term member, as we need another good mentor, especially on speaker issues.

 

[TLS Guy]

From what I've seen, both are bashed.

I appreciate the merits of the B&W design approach, but I think it creates a speaker that's more difficult than most to get sounding near perfect in typical listening spaces.

Well of course you can't consider a driver without equal scrutiny of the crossover.

I think B & W are of the same view as myself, that crossovers in the speech discrimination band are a problem, but often unavoidable. I really don't like speakers with crossovers in the 1 KHz to 2.5 KHz region. I think this is a leading cause of poor speech discrimination.
The problem is that there are very few decent wide band drivers around.

In the old B & W driver it was driven into cone break up mode at 4KHz. Now some drivers can be driven into break up and give a good account of themselves, but usually not. B & W just pushed that driver over the limit and it would have been better with a lower crossover point.

We are getting into a controversial area here. However I'm firmly of the view that you should not be cavalier about phase and time aberrations, which are actually different ways of looking at exactly the same thing. I think taking liberties with time in the speech discrimination band is a problem. I applaud B & W for recognizing that. In my view speaker designers do not pay nearly enough attention to this problem. This in not a problem that shows up in the frequency response graph. As I have pointed out before you could produce a speaker that had a perfect frequency response graph, but so much time aberration that it would be totally unlistenable, and speech incomprehensible. You would never know it from graphs you could present that would make the speaker look like an expensive reference job, but in fact totally useless.